Effect of Conductive Filler Size and Type on Thermal Properties of Asphalt Mixtures

This paper focuses on the improvement of thermal properties such as thermal conductivity, thermal diffusivity, and specific heat of asphalt mixtures using conductive fillers, and investigating the conduction performance by one-dimensional (1-D) simulation on pavements. Different asphalt mixtures used in this study was modified with milled carbon fiber, chopped carbon fiber, flake graphite powder and synthetic graphite powder individually. The conductivity properties of graphite and carbon fibers modified asphalt mixtures was measured and calculated to evaluate their conduction effects in order to obtain the appropriate kind and quantity of carbon fiber and graphite. The 1-D simulation was performed on a typical pavement design using finite difference method to comprehend the conduction performance taking place in pavement structure. Thermal testing and analysis results indicated that carbon fibers and graphite basically increase the thermal properties of asphalt mixtures. The simulation results presented the reliable heat conduction correlated with each conductive fillers.